The invention relates to an open-end spinning machine composed of a plurality of spinning assemblies with at least one maintenance device traveling along the open-end spinning machine. The maintenance device is provided with means for opening a spinning assembly and with means for advancing a cleaning device to a spinning rotor accessible as a result of the opening of the spinning assembly and having one open side, into which spinning rotor a cleaning element of the cleaning device enters while the spinning rotor is separated from its drive means.
Commonly owned pending U.S. applications Ser. Nos. 798,380, filed May 19, 1977 (title: Mobile Cleaning Device For An Open End Spinning Machine) and Ser. No. 774,539, filed Mar. 4, 1977, now U.S. Pat. No. 4,056,832 (title: Open-End Spinning Machine With A Plurality Of Spinning Units And With At Least One Servicing Device) also relate to cleaning apparatus for open-end spinning machines and may be consulted, as needed, for a further understanding of the present invention.
In a known design of the type described hereinabove (British Pat. No. 1,306,232), a suction nozzle is advanced to the spinning rotor, said nozzle cooperating with a peeling knife which enters the spinning rotor. Since a relative velocity is necessary between the cleaning element and the spinning rotor, the fact that the spinning rotor continues running (because of its inertia) after the drive is disconnected should be utilized. However, it has been shown in practice that this running down is insufficient for effective cleaning in most cases, since the spinning rotor is additionally braked by the cleaning element. However, in order to carry out maintenance work and especially to remove and replace the spinning rotor, it is desirable for the spinning rotor to be disconnected from its drive after the spinning assembly is opened, so that in any case the drive will be disconnected during the cleaning process.
An object of the invention is to design a maintenance device for an open-end spinning machine in such form that effective cleaning can be carried out even when the spinning rotor is no longer driven during the cleaning process. The invention contemplates providing that the maintenance device is equipped with means for driving the spinning rotor in question and/or controlling the rotational speed of the spinning rotor during cleaning operations.
This design ensures that the additional expense for the maintenance device remains limited while no substantial changes need be made in the individual spinning assemblies. In an advantageous embodiment of the invention, means are provided such that the cleaning element introduced into the spinning rotor is equipped with a drive which drives the cleaning element with movements directed at least approximately in the circumferential direction of the spinning rotor. This makes it possible to use the cleaning element itself as a drive means for the spinning rotor, so that no additional drives need be provided. In order to produce a sufficient difference in the circumferential velocity of the cleaining means and the spinnng rotor to be cleaned in this design, another feature of preferred embodiments of the invention provides that the drive is provided with a device for interrupting the drive and/or changing the speed and/or reversing the direction of rotation.
According to another feature of preferred embodiments of the invention, means are provided such that the cleaning device comprises a brake which can be advanced to the spinning rotor from the outside. Actuating this brake ensures that the spinning rotor again receives a differential velocity relative to the cleaning element, in the event that it has reached the circumferential velocity of the latter.
When the cleaning element sets the spinning rotor turning, there is a sufficient difference in velocity when cleaning begins between the circumference of the cleaning element and the circumferential velocity of the spinning rotor, but the two speeds become more and more similar as cleaning proceeds. Therefore, the above-mentioned measures are designed to ensure that after a certain period of time a sufficient difference is once again produced, ensuring effective cleaning.
The measure which provides for driving the spinning rotor with the aid of the maintenance device and especially with the aid of the cleaning element has the advantage that the cleaning element, during its cleaning process, need not change its initial position radially or circumferentially relative to the spinning rotor, resulting in a simplification of the design.
These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration, several embodiments in accordance with the present invention .